The goal of the proposed research is to develop a high-frequency, broadband, large-aperture ultrasound transducer for rapid 3-D ophthalmic imaging. TRS proposes to make high frequency piezoelectric ultrasound transducer arrays using photolithography to define micron-scale feature sizes and chemical etching to micro-machine the desired transducer structure. The key innovation behind the proposed technology is the combination of single crystal piezoelectrics with deep reactive ion etching (DRIE) to make very fine scale transducer structures with piezoelectric properties that surpass even those of low-frequency, ceramic-based transducers. For Phase I, TRS will demonstrate a 1-D, 30 MHz, linear array transducer with a bandwidth approaching 100%. In Phase II, a linear array with elevation elements will be developed for rapid volumetric scanning. The array will also be curved to match the surface of the eye. Successful completion of this program will eliminate the need for mechanically scanned single element transducers greatly improving patient comfort, decreasing scan time, and improving the accuracy of the 3-D pachymetry maps through reduced patient motion. The broad bandwidth will also facilitate both anterior and posterior imaging with 1 transducer. The device will thus improve the performance of ophthalmic ultrasound for a broad range of clinical applications including cataract treatment by lens replacement, LASIK, intraocular melanoma characterization, retinal imaging and glaucoma testing. [unreadable] [unreadable]